Com_admin_commands extremely high (90%) - what's going on?

(roughly ten hours uptime on this go, but I've had longer runs and these numbers tend to stay in proportion)

This is a webserver, running django through apache+mod_python, on a reasonably but not that busy (10K visits/day) site.

I've never seen Com_admin_commands so high, and I can't find any documentation that explains what it is, or why it's accounting for some 90% of my server's queries. The binlog seems to contain only the expect select/update/insert queries (many of which are less optimised than maybe they could be, but that's being worked on)

I should point out I'm not the web developer, so I can't talk about individual queries. If I restart the database server there are thousands of 'admin commands' run within seconds of restart - even if traffic to the website is low.

I have some experience of tuning MySQL (and I'm learning more by the hour!), and am in the process of making sure the various buffers and caches are set up to best effect, plus my web guy is optimising his queries - but I've never seen this before and it's really worrying me. 90% of all queries?!

A complete SHOW VARIABLES, SHOW STATISTICS and my.cnf is attached. Server's a quad core opteron with 4GB of ram, 64-bit debian stable, mysql v5.0.32. All tables are MyISAM, other storage engines are disabled to keep memory footprint down.

If anyone has any advice on what might be happening, I would really appreciate it. Thanks in advance.